Stayed here for three and a half months from Sep to Dec 2019. It's the fourth time I've stayed in this Niche Mono complex and it's great.
The apartment is new, clean and well equipped; pots and pans, washing machine, microwave, TV with Netflix built in, WiFi etc. It's a little more homely than the others I've stayed in at this complex as well, with some decorations etc.
Olga is the liaison for the host, and always responds very quickly to queries. We had a couple of minor issues (TV signal problem, parking) which is normal in these types of places, and Olga sorted them for us straight away.
The area is good. It's just over 1km to the nearest BTS (On Nut), which is around 10-12 minutes' walk. There's a big 7eleven next to the building, and several nice bars, coffee shops and restaurants between the apartment and the BTS (check out Laff Coffee). There's also a big Tesco Lotus next to the BTS, as well as a food night market and shopping mall. On Nut is a cheaper area to stay than others, such as Sukhumvit. This place costs about the same as a hotel, and is much more comfortable.
Overall, I was very happy with the stay and would recommend it :-)